A great part of our modern knowledge about the structure and composition of proteins originates from the analysis of the products formed by their hydrolysis. Since Braconnot, in 1820, hydrolysed gelatin with dilute sulfuric acid, proteins have been hydrolysed with acids at concentrations as high as sixteen normal. Hydrolysis has also been effected by heating proteins with barium hydroxide solutions or other alkalies and by incubating them with pancreatic and other proteolytic enzymes.

At the onset of puberty in the normal pullet, profound morphological and physiological changes occur under the influence of endogenous genadal hormones. The work about to be described forms part of a study of the biochemical changes evoked in the sexually immature pullet by the administration of gonadal hormones. The ultimate object of this study is to relate the similar puberal changes in the normal pullet to the endogenous hormonal influences responsible.

Probably no single protein has been the subject of as many chemical investigations as has casein. This is to be expected since casein is the main protein constituent of the milk of all mammals and because it can be readily isolated in a more or less pure state and with reasonably reproducible properties. For one hundred years following Mulder’s discovery that casein may be precipitated from milk by the addition of acid, casein was considered the typical example of a homogeneous protein. It was not until the classical solubility studies of Linderstrom-Lang were published, that casein was definitely shown to be a mixture of proteins.

The mineralogy of the soil has in recent years received considerable attention, and much progress has been made in the separation and identification of minerals in this field. The emphasis on mineralogical identification is due to the fact that a given mineral is not sufficiently characterized by its chemical composition alone. The bulk of the minerals in the soil may be considered to be of varying chemical composition, therefore, any given chemical analysis can be interpreted in many different ways as mixtures of two or more of these minerals.

Vitamin A is commonly determined by spectrophotometry or by measurement of the colour produced by its reaction with antimony trichloride. The complex nature of many vitamin A preparations makes it necessary to evaluate these physical and chemical methods against biological assays. Many such comparisons have been reported in the literature but the work carried out before 1948 is subject to the errors arising from the lack of a pure, stable, standard preparation. It is somewhat astonishing, therefore, to find that a comparatively limited use has been made of the biological assay since crystalline vitamin A became available. [...]

Leguminous plants occupy an exceptional place in the vegetable kingdom. Their roots have the ability to utilize the services of symbiotic bacteria for synthesis of proteins from atmospheric nitrogen and thus, unlike other plants, actually add nitrogen to the soil. They have also a comparatively greater content of protein in the stems, leaves and seeds. [...]

Remarkable morphological and physiological changes may be brought about by the administration of estrogenic hormones to the prepuberal pullet. These changes may include increases of the oviduct weight, liver weight, liver protein and liver lipid as well as of the levels of calcium, phosphorus, protein and lipid in the blood. There is some experimental evidence that these responses may be conditioned by the effects of the thyroid hormones. There is a somewhat more limited literature on the effects of the antithyroid agent, thiouracil, on estrogen-induced changes of serum calcium, serum protein, liver weight, liver protein and liver lipid.

Emphasis on the chemistry of phosphorus in soils arises from its importance as a plant nutrient and from the influence which the chemical form of the element has upon its utilization by plants. The importance of phosphorus in plant nutrition is demonstrated by the fact that more than 4,000,000 tons of phosphatic fertilizers are used in Canada and the United States each year.

The anaphylactoid shock in guinea pigs produced by enzymic casein-hydrolysates, has been determined by in vivo test and by the Schultz-Dale technique. It has been shown that hydrolysates with low transmittances are more prone to produce anaphylactoid reaction than hydrolysates with high transmittances. [...]

Fodsol soils constitute a large proportion of the soils of Eastern Canada. They are developed under woodland in cool humid conditions where rainfall exceeds evaporation. The profile from the surface downward consists essentially of an organic layer, a leached layer, and a layer of accumulation just above the parent rock. Thus the simplest podso1 profile consists of three horizons, namely: Ao ‘ the raw humus layer; A2, the leached siliceous layer; B, the layer of accumulation of sesquioxides. The Ao horizon of acid peaty organic matter is considered essential to the development of a true podsol. G.W. Robinson makes the following statement: “.... It would appear that an acid reaction is not in itself sufficient to cause podsolization. This may be readily shown in the laboratory by allowing 0.1 N solutions of hydrochloric acid and oxalic acid, respectively, to percolate through ferruginous sand. Alghough the pH of the hydrochloric acid is lower than that of the oxalic acid, the solvent action of the latter acid is considerably greater and quickly leads to a bleaching by removal of ferric oxide.....” R.T. Jones and J.S. Willcox have demonstrated in the laboratory that oxalic and tartaric acids will bring sesquioxides, from the upper part of the profile, into solution and deposit them lower down.[...]